Time synchronization build ntp server, cluster automatically synchronize time and ntpdate command~!

Environmental preparation

Two centos7, firewall closed, selinux closed
server (server): 192.168.112.153
client (client): 192.168.112.154

Step start

1. View the current system kernel

• Confirm that the server and client versions are the same

cat /etc/redhat-release

• Execution effect chart
  

2. Server installation service

yum -y install ntp

• After installation, check

3. Modify the configuration file

vim /etc/ntp.conf 

• Comment out line 8
  
• Comment out lines 13, 14
  
• Remove the comment (#) on line 17 and modify the local IP
  
  resolution: Allow updated IP address segment to synchronize time
• Comment out lines 21 to 24
  
• 25.26 line added

Analysis: If the network time synchronization server is not available, provide services to the client based on the local time

4. Start the service

systemctl start ntpd     启动
systemctl enable ntpd    开机自启

5. View service status

systemctl status ntpd

ntp check to

see if it is synchronized

6. Verify time synchronization

Client install ntp service

 yum -y install ntp

synchronised time

ntpdate -u 192.168.112.153

Check time

date

Anti-thunder

• • • If the time on the server side changes or changes manually,
      remember to restart the service! ! !
• Change the verification rendering

1. Server modification, restart
   
2. Client side synchronization verification